Biosensors are used to obtain information about molecules that can be used to identify the molecules. The molecules may be suspended in a solution or may be present in gaseous form and attach either directly or indirectly to electrodes of the biosensor.
For example, detection of nucleic acids often involves hybridisation to DNA that is in contact with electrodes of the biosensor. Other types of molecules may directly attach to the electrodes of the biosensor. The attached molecules influence electrical properties of the biosensor which can be detected by impedance or capacitance measurements at the electrodes.
Fabrication of biosensors typically involves many processing steps. The biosensor may include a series of electrodes which are closely spaced from each other by a distance of 100 nm or less. Fabrication of such a bio-sensor typically involves a sequence of masking and etching steps similar to those used for the fabrication of integrated electronic devices. The biosensor typically includes portions having a molecular dimension which makes fabrication of the biosensor especially difficult. Further, the fabrication of the electrodes at well defined positions which are separated only by a distance in the nanometer range typically involves complicated aligning processing steps. There is a need for technological advancement that simplifies the fabrication of such biosensors.